refactor: update PDF comparison types and enhance UI for better usability

- Refactored CompareState to import from a centralized type definition.
- Enhanced the compare-pdfs.html layout with improved styles for overlay and side-by-side modes.
- Added new CSS styles for various UI components including panels, buttons, and highlights.
- Implemented a new sidebar for displaying change summaries and filters.
- Created unit tests for text comparison logic, including diffing text runs and page pairing.
- Added tests for text normalization functions to ensure proper handling of punctuation and character normalization.

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "bento-pdf",
-  "version": "2.4.0",
+  "version": "2.4.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "bento-pdf",
-      "version": "2.4.0",
+      "version": "2.4.1",
       "license": "AGPL-3.0-only",
       "dependencies": {
         "@fontsource/cedarville-cursive": "^5.2.7",
@@ -30,6 +30,7 @@
         "blob-stream": "^0.1.3",
         "bwip-js": "^4.8.0",
         "cropperjs": "^1.6.2",
+        "diff": "^8.0.3",
         "embedpdf-snippet": "file:vendor/embedpdf/embedpdf-snippet-2.3.0.tgz",
         "heic2any": "^0.0.4",
         "highlight.js": "^11.11.1",
@@ -55,11 +56,13 @@
         "markdown-it-task-lists": "^2.1.1",
         "markdown-it-toc-done-right": "^4.2.0",
         "mermaid": "^11.12.3",
+        "microdiff": "^1.5.0",
         "node-forge": "^1.3.3",
         "papaparse": "^5.5.3",
         "pdf-lib": "^1.17.1",
         "pdfjs-dist": "^5.4.624",
         "pdfkit": "^0.17.2",
+        "pixelmatch": "^7.1.0",
         "postal-mime": "^2.7.3",
         "rete": "^2.0.6",
         "rete-area-plugin": "^2.1.5",
@@ -6353,6 +6356,15 @@
       "integrity": "sha512-ED3jP8saaweFTjeGX8HQPjeC1YYyZs98jGNZx6IiBvxW7JG5v492kamAQB3m2wop07CvU/RQmzcKr6bgcC5D/Q==",
       "license": "MIT"
     },
+    "node_modules/diff": {
+      "version": "8.0.3",
+      "resolved": "https://registry.npmjs.org/diff/-/diff-8.0.3.tgz",
+      "integrity": "sha512-qejHi7bcSD4hQAZE0tNAawRK1ZtafHDmMTMkrrIGgSLl7hTnQHmKCeB45xAcbfTqK2zowkM3j3bHt/4b/ARbYQ==",
+      "license": "BSD-3-Clause",
+      "engines": {
+        "node": ">=0.3.1"
+      }
+    },
     "node_modules/diffie-hellman": {
       "version": "5.0.3",
       "resolved": "https://registry.npmjs.org/diffie-hellman/-/diffie-hellman-5.0.3.tgz",
@@ -9068,6 +9080,12 @@
         "uuid": "^11.1.0"
       }
     },
+    "node_modules/microdiff": {
+      "version": "1.5.0",
+      "resolved": "https://registry.npmjs.org/microdiff/-/microdiff-1.5.0.tgz",
+      "integrity": "sha512-Drq+/THMvDdzRYrK0oxJmOKiC24ayUV8ahrt8l3oRK51PWt6gdtrIGrlIH3pT/lFh1z93FbAcidtsHcWbnRz8Q==",
+      "license": "MIT"
+    },
     "node_modules/micromark-util-character": {
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/micromark-util-character/-/micromark-util-character-2.1.1.tgz",
@@ -9896,6 +9914,18 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/pixelmatch": {
+      "version": "7.1.0",
+      "resolved": "https://registry.npmjs.org/pixelmatch/-/pixelmatch-7.1.0.tgz",
+      "integrity": "sha512-1wrVzJ2STrpmONHKBy228LM1b84msXDUoAzVEl0R8Mz4Ce6EPr+IVtxm8+yvrqLYMHswREkjYFaMxnyGnaY3Ng==",
+      "license": "ISC",
+      "dependencies": {
+        "pngjs": "^7.0.0"
+      },
+      "bin": {
+        "pixelmatch": "bin/pixelmatch"
+      }
+    },
     "node_modules/pkg-dir": {
       "version": "5.0.0",
       "resolved": "https://registry.npmjs.org/pkg-dir/-/pkg-dir-5.0.0.tgz",
@@ -9925,6 +9955,15 @@
       "resolved": "https://registry.npmjs.org/png-js/-/png-js-1.0.0.tgz",
       "integrity": "sha512-k+YsbhpA9e+EFfKjTCH3VW6aoKlyNYI6NYdTfDL4CIvFnvsuO84ttonmZE7rc+v23SLTH8XX+5w/Ak9v0xGY4g=="
     },
+    "node_modules/pngjs": {
+      "version": "7.0.0",
+      "resolved": "https://registry.npmjs.org/pngjs/-/pngjs-7.0.0.tgz",
+      "integrity": "sha512-LKWqWJRhstyYo9pGvgor/ivk2w94eSjE3RGVuzLGlr3NmD8bf7RcYGze1mNdEHRP6TRP6rMuDHk5t44hnTRyow==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=14.19.0"
+      }
+    },
     "node_modules/points-on-curve": {
       "version": "0.2.0",
       "resolved": "https://registry.npmjs.org/points-on-curve/-/points-on-curve-0.2.0.tgz",